Rubber auxilliary suspension with stages under tension for vehicle axles in general

ABSTRACT

An auxiliary suspension system operating on stages of loaded rubber for axles of vehicles in general includes a pair of concentric tubes, one outer and one inner, with rubber applied to the surfaces of contact. As the tubes turn one inside the other, they put the rubber into torsion. The system can have two integrated phases or it can be a hybrid system. The suspension system connects the vehicle chassis to the axle of the wheels using a lever arm attached to the outer tube and a support that holds the inner tube and a system of torsion control at the other end. The suspension system has features including a torsion lever that changes longitudinal movement of the tensioning element into angular movement that is transmitted to the anchoring tube to stretch the rubber, and a torsion arm or crossbeam that is fixed to a covering box at one end and that has a hole where a fork-shaped tensioning element passes, providing a supporting point to the tensioning element and generating a longitudinal movement to permit torsion adjustment of the rubber to a desired level.

RELATED APPLICATIONS

This application is a continuation of application Ser. No. 10/475,749,now U.S. Pat. No. 7,264,252, which is the National Stage ofInternational Application No. PCT/MX02/00033, filed on Apr. 24, 2002.

BACKGROUND

Some suspension systems have been developed such as metal sheets,helicoidal springs, air bags, etc. They all seek to allow the vehicle totravel comfortably on roads with potholes, curves, stones, etc. whichthey face frequently. Thus, as the comfort of the suspension isimportant, it is also necessary to have other characteristics such asloading capacity, stability, duration, low cost, simplicity ofoperation, reduction of vibration, safety, low maintenance cost, etc.Since every suspension has advantages and disadvantages the suspensionof the present invention was designed which attempts to complementvehicles which have some suspension system already installed, so as toreduce deficiencies and to improve comfort.

One of the main disadvantages of existing systems is that the vehicledoesn't have an appropriate level of comfort throughout the load range.So, there are systems in which, when the vehicle is without load orlighty loaded, it jumps, vibrates, bounces or is unstable on windingroads, etc. and when it is loaded it works very good, but the vehiclewon't always be totally loaded. Conversely, some systems are moderatelycomfortable without load but when they are loaded, they lower too much,they are unstable, visibility gets low, etc. In both cases, a suspensionsystem using loaded rubber stages can be installed according to thepresent invention: in the first case, as a first stage to increasecomfort and stabilize the vehicle when it is without load or almostwithout load, and in the second case it is used to improve loadingcharacteristics, reduce the amount of vehicle lowering and increase thestability working as a second auxiliary stage.

The suspension system of loaded rubber can be made with two or moreintegrated phases, this way it can be used as an integrated suspensionsystem which gives the vehicle an appropriate level of comfort in allload ranges and excellent stability, safety, low cost and alsomaintenance. The torsion control system also allows the balancing of thevehicle in an easy way when the rubber has any kind of damage caused byuse, by adjusting a nut and counter nut which will be described below.

SUMMARY OF THE INVENTION

This invention relates to a novel auxiliary suspension system in stagesfor vehicles in general, applied to an axle, tandem axles or auxiliarywheels.

When using a suspension according to an embodiment of this invention,rear suspensions (passengers and cargo) are softened when loads are in arange of 0% to 50% of the load capacity, resulting, with this suspensionmechanism, in greater comfort in this range for these vehicles users,while when subjected to over 50% of the load capacity, only springs,such as in present vehicles, operate.

Another aspect of an embodiment of the present invention is that thissuspension has a 25% load capacity by virtue of the fact that one systemis preferably installed in a vehicle chassis on each side. The systemattaches to the bumper's fastening points or other ones contained in thechassis and/or back hangar and the spring bushing will be coupled to thelever arm bushing of the suspension mechanism through a swing. Thereforethe two parts would provide support up to 50% of the load capacity andthe rest would be shared by the two springs. That is to say, thesuspension mechanism will work with the springs from 0% to 50% of load,considering this as a first stage of operation and when over 50% of theload is applied, spring action or function would be started, thussprings work from 50% to 100% of the load, this being a second stage ofoperation.

The auxiliary suspension system of the present invention is comprised ofa pair of concentric tubes with rubber added to its contact surfaces,such that when one tube turns inside the other one, the rubber is putinto torsion. This system can have two integrated stages or it can be ahybrid system, using as a first or second stage some suspension systemalready installed in the vehicle, which can be a spring or conventionalmetal sheets system. The suspension of an embodiment of the presentinvention couples the vehicle chassis to the wheel axle using a leverarm attached to the outer tube and a support which holds the inner tubeand its torsion control system at the other end. These parts and someother characteristics of the suspension mechanism are described moreclearly below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a lateral view of the loaded rubber suspension of a stage.

FIG. 2 shows the exploded view of the suspension of a stage.

FIG. 3 shows a rear view of a stage loaded and installed in the chassis.

FIG. 4 shows assembly of the loaded rubber suspension as a first stagetogether with a suspension of metal sheets which acts as a second stage.

FIG. 5 shows the lateral view of a suspension of two stages integratedwith loaded rubber.

FIG. 6 shows a rear view of a suspension of two integrated rubberstages.

FIG. 7 shows an exploded view of a suspension of two loaded rubberstages.

FIG. 8 shows the assembly of one side of a two stage suspension in avehicle with a shaft, two wheels and a chassis.

DETAILED DESCRIPTION

The suspension system of the present invention can be applied to anaxle, tandem axles or to auxiliary wheels. First, an embodiment of theinvention will be described as applied to a simple axle with two wheelsand the operation will be described as a first stage of a system withmetal sheets suspension. Second, an alternative embodiment will bedescribed as applied to a suspension of two integrated stages withloaded rubber.

In FIGS. 1 and 2 number (1) is a lever used to transmit to the reactiontube (5) or outer tube in FIG. 2 the force coming from shaft (17) inFIG. 4 through steel sheets springs (16) in FIG. 4 which are attached tothe lever by means of swing (20) in FIG. 4. Number (2) in FIGS. 1 and 2is an anchoring tube or inner steel tube which transmits to the rubber,anchored through vulcanization of its outer surfaces, an angularmovement which causes it to stretch the rubber until reaching thedesired adjustment point. Number (3) in FIGS. 1 and 2 is a covering orsteel plate with three holes, two of equal diameters which serve asfastening points and one of a bigger diameter serving to hold anchoringtube (2) in FIG. 2 when the system is loaded. This plate is screwed onthe chassis of the vehicle.

Number (5) in FIG. 2 is a reaction tube and it is used to receive aforce coming from lever (1) in FIG. 2 and to transmit it to the rubberadded to its inner surface which causes it to generate a reaction forcethat balances system. Number (6) in FIGS. 1 and 2 is a torsion lever andit changes longitudinal movement of the tensioning element into anangular movement which is transferred to the anchoring tube to stretchthe rubber. Number (7) in FIGS. 1 and 2 is a torsion arm or steelcrossbeam attached to the covering box (3) in FIG. 2 at one end andhaving a hole through which passes the fork shaped tensioning element(8) in FIGS. 1 and 2 which functions to give a supporting point forattaching the fork shaped tensioning element (8) in FIG. 2.

Number (8) in FIGS. 1 and 2 is a fork-shaped tensioning element and itserves to generate a longitudinal movement to permit adjustment of therubber torsion to the desired level. Number (9) in FIGS. 1 and 2 areadjustment nuts and they serve first to change the circular movement ofnuts over the threads of the fork-shaped tensioning element (8) in FIG.2, into a controlled longitudinal movement and second they serve ascounter nuts to make sure that when the adjustment is made it does notmove. Bolt (10) in FIG. 2 is a small steel bar and it serves to join thefork-shaped tensioning element to the torsion lever. Number (11) inFIGS. 1 and 2 is a stop member and it serves to limit the displacementof the lever arm and it determines the working point of each stage,because when the stop member stops the arm, this prevents thetransmission of more force to reaction tube (5) in FIG. 2 and from thatpoint only the second stage operates, such as in this case is springs ofsteel sheets (16) in FIG. 4.

Number (12) in FIGS. 1 and 2 is a supporting crossbeam or steel supportthat allows placement of the run limit (24) in FIG. 4 and to hold thecomplete suspension system box (between plate (3) and box base (4) inFIG. 2) to the back hangar (22) in FIG. 4 and accordingly it is firmlyheld to the chassis on the part designed to support the load. Rubberpart (13) in FIGS. 2 and 7 is a compound of natural and synthetic rubbervulcanized and added to contact the surfaces of the reaction andanchoring tubes which permits it to be resistant to fatigue, torsion,vibration, breaking, etc., as such, it serves to have the systembalanced throughout the load range which the suspension of a stage isdesigned for, and it also can be used with a steel core (not shown).

Considering the second stage of the suspension system, the rubber part(14) in FIG. 7 is a compound of natural and synthetic rubber vulcanizedand applied to contact the surfaces of anchoring tubes (2) in FIG. 2 andsecond stage reaction tubes (15) in FIG. 7. The rubber is preferablyresistant to fatigue, torsion, vibration, breaking, etc., and it servesto have the system balanced throughout the load range for which thesecond stage is designed for. Number (15) in FIG. 7 is the second stagereaction tube and has as a purpose to receive a force coming fromactuator (23) in FIG. 6, attached to the first stage and to transmitthis force against the actuator attached to the second stage and thenagainst the rubber applied to its inner surface. This action willgenerate a reaction force to balance the system with the forces of thefirst and second stages being combined.

Number (16) in FIG. 4 are the springs of metallic sheets and they arepart of suspension systems in wide use and they are used as a secondstage when the system is a hybrid system and they have as a purpose toflex themselves and to change a vertical movement provoked by variationsof load or surface into mixed movements with vertical and horizontalcomponents. Number (17) in FIG. 4 identifies the vehicle axle whichholds the tires on its ends and the axle is held to the springs throughholders and serves as a way to couple the vehicle floor and thesuspension. Vehicle chassis (18) in FIG. 4 is the rigid steel frame overwhich the suspension box is attached and it is the connection betweenthe suspension system and the vehicle body. Shock absorber (19) in FIG.4 is a mechanism used to reduce shock and speed of vertical movement.Swing (20) in FIGS. 4 and 8 is a pair of crossbeams with rubber or nylonbushings which couple springs of metallic sheets in FIG. 4 or a supportbar in FIG. 8 to the lever. Front hangar (21) in FIGS. 4 and 8 is asteel part attached to the chassis of the vehicle in a place designed tohold the load in front of the suspension. Back hangar (22) in FIGS. 4and 8 is a steel part attached to the chassis of the vehicle in a placedesigned to support loading in the rear.

Number (23) in FIG. 6 identifies the actuators fixed to the first andsecond stages which are separated and they serve to determine from whatquantity of movement and loading the two stages will act as only onestage. Number (24) in FIG. 4 identifies the run limit of the lever thatdetermines the amount of movement allowed in the first stage inconjunction with the springs of metallic sheets. Number (25) in FIGS. 5and 6 are triangles of steel plate use to make the suspension boxstructure act as a rigid body. Number (26) in FIGS. 3 and 6 are holdingscrews or steel threaded bolts with nuts and washers and they are usedto fix suspension box base and covering (3) and (4) in FIGS. 1 and 2 tothe chassis (18) in FIG. 4. Number (27) in FIG. 8 is a holding bar ormetal rectangular tube and it serves to hold the axle in a fixedposition with respect to the front hangar (21) in FIG. 4 and to transmitthe force of the axle reaction (17) in FIG. 4 to the swing (20) in FIG.4.

One aspect of the present invention is an auxiliary suspension systemusing stages of loaded rubber applied to axles of vehicles in general.The upper part comprises a box or a bent steel plate with a hole in thecenter that serves as a support to the parts which are attached to thebox base located in the lower part. There is also a steel plate withthree holes, two of equal diameter that serve as fastening points andone of a bigger diameter that serves to hold an anchoring tube when theunit is assembled. This plate is screwed on the chassis of the vehicle,and it also includes a lever that transmits force coming from the axleto a reaction tube, where the wheel is assembled through the springs ofsteel sheets which are attached to the lever through a swing. The systemalso includes an anchoring tube or steel tube that transmits to thevulcanized rubber, anchored on its outer surface, an angular movement,which causes the rubber to stretch until reaching the desired adjustmentpoint. The reaction tube receives force coming from the lever and ittransmits it to the rubber contacting its inner surface causing it togenerate a reaction force that balances the system.

The system also includes a torsion lever that changes the longitudinalmovement of a tensioning element into an angular movement that transmitsto the anchoring tube to stretch the rubber, and a torsion arm orcrossbeam that is attached to the covering box at one end and having ahole through it for passing a fork-shaped tensioning element. Thetorsion arm provides an attachment point for the tensioning element andit is also used to generate a longitudinal movement that permits theadjustment of the rubber torsion to the desired level such that thesuspension operates properly.

Another aspect of the present invention is an auxiliary suspensionsystem using stages of loaded rubber, for axles of vehicles in general,as described above that also includes two adjustment nuts used to changethe circular movement of the nut over the fork-shaped tensioning elementinto a controlled longitudinal movement and also is used as a counternut to make sure that the adjustment does not move. A bolt for thefork-shaped tensioning element or a small steel bar is used to join thefork-shaped tensioning element to the tension lever. Also provided is astop used as a movement limit of the lever arm which determines theworking point of each stage, because when the stop prevents the leverarm from moving, this prevents the transmission of more force to thereaction tube and at that point only the second stage is operating,which it is the springs of steel sheets in this case.

A steel crossbeam determines the run limit and holds the suspension box(covering and base of box) to the back hangar that is firmly held to thechassis such that the load is supported. Rubber is applied to contactthe surfaces of the anchoring and reaction tubes that is resistant tofatigue, torsion, breaking, etc. As such, the suspension system isbalanced throughout the loading range of one or two stages ofsuspension.

Another aspect of the present invention is an auxiliary suspensionsystem using stages of loaded rubber for axles of vehicles in general asdescribed above including a second stage reaction tube that receivesforce coming from an actuator attached to the first stage and transmitsit to an inner surface which causes it to generate a reaction force tobalance the system with the combined forces of the first and secondstages. Springs of steel sheets can be used as a second stage when thesystem is a hybrid system and they have as a purpose to flex themselvesand to change vertical movement caused by variation of load or surfaceinto a mixed movement with horizontal and vertical components. An axleis attached to the tires on its ends and the axle is held to the springsthrough holders and it is used to join floor and suspension. A chassisor rigid steel frame is fixed over the suspension box, and a shockabsorber can be used to reduce the shock and speed of vertical movement.A swing with rubber or nylon bushings couples the springs and the lever,and back and front hangars or steel parts held to the chassis are usedto support the front and back of the suspension.

In some embodiments, actuators attached to the first and second stagesare separated and they serve to determine from what quantity of loadmovement the two stages will act as only one stage. Also, the run limitof the lever combined with the stop determines the quantity of movementallowed in the first stage in conjunction with springs of metallicsheets. In some embodiments, triangles of steel plate are used to makethe box structure of the suspension system behave as a rigid body and asupporting bar or rectangular tube serves to hold the axle in a fixedposition with respect to the front hangar and to transmit strength ofthe reaction force from the axle to the swing.

1. A method of equipping a vehicle with an auxiliary suspensionapparatus comprising the steps of: providing a central shaft; providingan outer housing; providing an elastomer disposed between said centralshaft and said outer housing forming a flexible spacer, wherein radialdisplacement between said central shaft and said outer housing appliestorsion to said elastomer; providing a first lever attached to saidcentral shaft, wherein movement of said first lever causes said centralshaft to be displaced radially such that torsion is applied to saidelastomer, and wherein torsion is retained in said elastomer; couplingsaid first lever to the chassis of said vehicle; coupling said outerhousing to a vehicle suspension system; providing a threaded shaftattached to said first lever; providing an adjustable nut on saidthreaded shaft; and wherein said step of coupling said first levercomprises adjustably mounting said shaft to a support member.
 2. Amethod of equipping a vehicle with an auxiliary suspension apparatuscomprising the steps of: providing a central shaft; providing an outerhousing; providing an elastomer disposed between said central shaft andsaid outer housing forming a flexible spacer, wherein radialdisplacement between said central shaft and said outer housing appliestorsion to said elastomer; providing a first lever attached to saidcentral shaft, wherein movement of said first lever causes said centralshaft to be displaced radially such that torsion is applied to saidelastomer, and wherein torsion is retained in said elastomer; couplingsaid first lever to the chassis of said vehicle; providing a secondlever attached to said outer housing; and coupling said second lever toa vehicle suspension system; wherein said step of coupling said secondlever comprises attaching said second lever to a vehicle springmechanism.
 3. The method of claim 1 wherein said elastomer comprises acompound of natural and synthetic rubber that has been vulcanized.
 4. Amethod of equipping a vehicle with an auxiliary suspension apparatuscomprising the steps of: providing a central shaft; providing a firstouter housing; providing a first elastomer disposed between said centralshaft and said first outer housing forming a first flexible spacer,wherein radial displacement between said central shaft and said firstouter housing applies torsion to said first elastomer; providing asecond outer housing; providing a second elastomer disposed between saidcentral shaft and said second outer housing forming a second flexiblespacer, wherein radial displacement between said central shaft and saidfirst outer housing does not apply torsion to said second elastomer in afirst range of movement and does applies torsion to said secondelastomer in a second range of movement; providing a first leverattached to said central shaft, wherein movement of said first levercauses said central shaft to be displaced radially such that torsion isapplied to said first elastomer, wherein torsion is retained in saidfirst elastomer; coupling said first lever to the chassis of saidvehicle; and coupling said first outer housing to a vehicle suspensionsystem.
 5. The method of claim 4 further comprising the steps of:providing a threaded shaft attached to said first lever; providing anadjustable nut on said threaded shaft; and wherein said step of couplingsaid first lever comprises adjustably mounting said threaded shaft to asupport member.
 6. The method of claim 4 further comprising the stepsof: providing a first actuator attached to said first elastomer;providing a second actuator attached to said second elastomer; andwherein when said first actuator is in contact with said secondactuator, radial displacement between said central shaft and said firstouter housing applies torsion to said first elastomer and to said secondelastomer; and wherein when said first actuator is not in contact withsaid second actuator, radial displacement between said central shaft andsaid first outer housing applies torsion to said first elastomer anddoes not apply torsion to said second elastomer.
 7. The method of claim4 wherein said first elastomer and said second elastomer comprise acompound of natural and synthetic rubber that has been vulcanized. 8.The method of claim 1 wherein said elastomer comprises a compound ofnatural and synthetic rubber that has been vulcanized.
 9. A method ofequipping a vehicle with an auxiliary suspension apparatus comprisingthe steps of: providing a central shaft; providing an outer housing;providing an elastomer disposed between said central shaft and saidouter housing forming a flexible spacer, wherein radial displacementbetween said central shaft and said outer housing applies torsion tosaid elastomer; providing a first lever attached to said central shaft,wherein movement of said first lever causes said central shaft to bedisplaced radially such that torsion is applied to said elastomer, andwherein torsion is retained in said elastomer; coupling said first leverto a vehicle suspension system, wherein said step of coupling said firstlever comprises attaching said first lever to a vehicle springmechanism; providing a second lever attached to said outer housing; andcoupling said second lever to the chassis of said vehicle.
 10. A methodof equipping a vehicle with an auxiliary suspension apparatus comprisingthe steps of: providing a central shaft; providing a first outerhousing; providing a first elastomer disposed between said central shaftand said first outer housing forming a first flexible spacer, whereinradial displacement between said central shaft and said first outerhousing applies torsion to said first elastomer; providing a secondouter housing; providing a second elastomer disposed between saidcentral shaft and said second outer housing forming a second flexiblespacer, wherein radial displacement between said central shaft and saidfirst outer housing does not apply torsion to said second elastomer in afirst range of movement and does applies torsion to said secondelastomer in a second range of movement; providing a first leverattached to said central shaft, wherein movement of said first levercauses said central shaft to be displaced radially such that torsion isapplied to said first elastomer, wherein torsion is retained in saidfirst elastomer; coupling said first lever to a vehicle suspensionsystem; and coupling said first outer housing to the chassis of saidvehicle.